They can be attractive on some girls if it complements the rest of their style, but they're entirely unnecessary and are by no means a way to become universally more attractive. Don't get one unless you feel personally compelled to. If your friends are trying to convince you, its probably because seeing you get one will make them feel more validated in their own choices to get one.
septum piercings are NOT cute but the little ones in the side are cute in my opinion. I think what makes them cute is they're not overly popular (as far as I have noticed). Plus for some reason, they just make a girl look different. I don't have a great explanation for it. :/ If you do get the side piercing, it hurts but then again you may have a higher pain tolerance than me. But it's worth it. I've had mine for over three years and I still love the way it looks. A lot of guys think they're hot/sexy while some don't but the main thing is that you think it is, of course. hopefully that answered your question somewhat.